diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/fuse_common.h | 39 | ||||
| -rw-r--r-- | include/fuse_kernel.h | 23 | ||||
| -rw-r--r-- | include/fuse_lowlevel.h | 13 |
3 files changed, 71 insertions, 4 deletions
diff --git a/include/fuse_common.h b/include/fuse_common.h index a614fb0..ba4b127 100644 --- a/include/fuse_common.h +++ b/include/fuse_common.h @@ -105,6 +105,11 @@ struct fuse_file_info { /** Requested poll events. Available in ->poll. Only set on kernels which support it. If unsupported, this field is set to zero. */ uint32_t poll_events; + + /** Passthrough backing file id. May be filled in by filesystem in + * create and open. It is used to create a passthrough connection + * between FUSE file and backing file. */ + int32_t backing_id; }; @@ -469,6 +474,18 @@ struct fuse_loop_config_v1 { #define FUSE_CAP_DIRECT_IO_ALLOW_MMAP (1 << 28) /** + * Indicates support for passthrough mode access for read/write operations. + * + * If this flag is set in the `capable` field of the `fuse_conn_info` + * structure, then the FUSE kernel module supports redirecting read/write + * operations to the backing file instead of letting them to be handled + * by the FUSE daemon. + * + * This feature is disabled by default. + */ +#define FUSE_CAP_PASSTHROUGH (1 << 29) + +/** * Ioctl flags * * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine @@ -598,9 +615,29 @@ struct fuse_conn_info { unsigned time_gran; /** + * When FUSE_CAP_PASSTHROUGH is enabled, this is the maximum allowed + * stacking depth of the backing files. In current kernel, the maximum + * allowed stack depth if FILESYSTEM_MAX_STACK_DEPTH (2), which includes + * the FUSE passthrough layer, so the maximum stacking depth for backing + * files is 1. + * + * The default is FUSE_BACKING_STACKED_UNDER (0), meaning that the + * backing files cannot be on a stacked filesystem, but another stacked + * filesystem can be stacked over this FUSE passthrough filesystem. + * + * Set this to FUSE_BACKING_STACKED_OVER (1) if backing files may be on + * a stacked filesystem, such as overlayfs or another FUSE passthrough. + * In this configuration, another stacked filesystem cannot be stacked + * over this FUSE passthrough filesystem. + */ +#define FUSE_BACKING_STACKED_UNDER (0) +#define FUSE_BACKING_STACKED_OVER (1) + unsigned max_backing_stack_depth; + + /** * For future use. */ - unsigned reserved[22]; + unsigned reserved[21]; }; struct fuse_session; diff --git a/include/fuse_kernel.h b/include/fuse_kernel.h index e7418d1..897f654 100644 --- a/include/fuse_kernel.h +++ b/include/fuse_kernel.h @@ -211,6 +211,10 @@ * 7.39 * - add FUSE_DIRECT_IO_ALLOW_MMAP * - add FUSE_STATX and related structures + * + * 7.40 + * - add max_stack_depth to fuse_init_out, add FUSE_PASSTHROUGH init flag + * - add backing_id to fuse_open_out, add FOPEN_PASSTHROUGH open flag */ #ifndef _LINUX_FUSE_H @@ -246,7 +250,7 @@ #define FUSE_KERNEL_VERSION 7 /** Minor version number of this interface */ -#define FUSE_KERNEL_MINOR_VERSION 39 +#define FUSE_KERNEL_MINOR_VERSION 40 /** The node ID of the root inode */ #define FUSE_ROOT_ID 1 @@ -353,6 +357,7 @@ struct fuse_file_lock { * FOPEN_STREAM: the file is stream-like (no file position at all) * FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE) * FOPEN_PARALLEL_DIRECT_WRITES: Allow concurrent direct writes on the same inode + * FOPEN_PASSTHROUGH: passthrough read/write operations for this open file */ #define FOPEN_DIRECT_IO (1 << 0) #define FOPEN_KEEP_CACHE (1 << 1) @@ -361,6 +366,7 @@ struct fuse_file_lock { #define FOPEN_STREAM (1 << 4) #define FOPEN_NOFLUSH (1 << 5) #define FOPEN_PARALLEL_DIRECT_WRITES (1 << 6) +#define FOPEN_PASSTHROUGH (1 << 7) /** * INIT request/reply flags @@ -449,6 +455,7 @@ struct fuse_file_lock { #define FUSE_CREATE_SUPP_GROUP (1ULL << 34) #define FUSE_HAS_EXPIRE_ONLY (1ULL << 35) #define FUSE_DIRECT_IO_ALLOW_MMAP (1ULL << 36) +#define FUSE_PASSTHROUGH (1ULL << 37) /* Obsolete alias for FUSE_DIRECT_IO_ALLOW_MMAP */ #define FUSE_DIRECT_IO_RELAX FUSE_DIRECT_IO_ALLOW_MMAP @@ -761,7 +768,7 @@ struct fuse_create_in { struct fuse_open_out { uint64_t fh; uint32_t open_flags; - uint32_t padding; + int32_t backing_id; }; struct fuse_release_in { @@ -877,7 +884,8 @@ struct fuse_init_out { uint16_t max_pages; uint16_t map_alignment; uint32_t flags2; - uint32_t unused[7]; + uint32_t max_stack_depth; + uint32_t unused[6]; }; #define CUSE_INIT_INFO_MAX 4096 @@ -1049,9 +1057,18 @@ struct fuse_notify_retrieve_in { uint64_t dummy4; }; +struct fuse_backing_map { + int32_t fd; + uint32_t flags; + uint64_t padding; +}; + /* Device ioctls: */ #define FUSE_DEV_IOC_MAGIC 229 #define FUSE_DEV_IOC_CLONE _IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t) +#define FUSE_DEV_IOC_BACKING_OPEN _IOW(FUSE_DEV_IOC_MAGIC, 1, \ + struct fuse_backing_map) +#define FUSE_DEV_IOC_BACKING_CLOSE _IOW(FUSE_DEV_IOC_MAGIC, 2, uint32_t) struct fuse_lseek_in { uint64_t fh; diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h index 2ada62b..cb38115 100644 --- a/include/fuse_lowlevel.h +++ b/include/fuse_lowlevel.h @@ -1397,6 +1397,19 @@ int fuse_reply_attr(fuse_req_t req, const struct stat *attr, int fuse_reply_readlink(fuse_req_t req, const char *link); /** + * Setup passthrough backing file for open reply + * + * Possible requests: + * open, opendir, create + * + * @param req request handle + * @param fd backing file descriptor + * @return positive backing id for success, 0 for failure + */ +int fuse_passthrough_open(fuse_req_t req, int fd); +int fuse_passthrough_close(fuse_req_t req, int backing_id); + +/** * Reply with open parameters * * currently the following members of 'fi' are used: |